Published: Friday 30 September 2005

abundant bacteria: Scientists say soil contains 100 times more bacteria species than believed. Previous studies estimated a gramme of unpolluted soil contained about 10,000 bacteria species. But a fresh analysis of soil data by researchers at the Los Alamos National Laboratory in New Mexico, the US, suggests the actual number is probably closer to 1 million or more. The old estimate was based on the assumption that all the bacteria species in a sample were equally abundant. But some bacteria species probably have fewer individuals than others, just like it is in the world of plants and animals.

cow power: A new study suggests microorganisms found in cow waste may provide a reliable source of electricity. Results showed microbes in about half a litre of fluid extracted from the rumen, the largest chamber of a cow's stomach, produced about 600 millivolts of electricity. That's about half the voltage needed to run one rechargeable AA-sized battery, said study co-author Ann Christy of the Ohio State University in the US. While rumen fluid itself won't be used as an energy source, some of the microorganisms found in the fluid are also found in cow dung, which may prove to be a good source for generating electricity.

small rnas: Scientists from the University of Delaware in the US have discovered 10 times more small ribonucleic acids (RNAs) in Arabidopsis (a weed of the mustard family) than previously identified. The research, conducted over a year and a half by teams from laboratories headed by Pamela J Green and Blake C Meyers, sequenced about 2.2 million small RNAs from seedlings and flowers of the plant. Green said small RNAs play an important role in regulating genes in both plants and animals. They have also been associated with processes such as response to stress.

tsunami analysis: A fresh analysis of last year's tsunami in the Indian Ocean shows it was so powerful it circled the globe at least twice. Swells ranging from a few centimetres to one metre were recorded along the west coast of the US, the east coast of Brazil and other distant locations, says Frank Gonzalez, head of tsunami research for the National Oceanic and Atmospheric Administration in Seattle, the US. Waves in Halifax, Nova Scotia, and Peru -- 22,000 and 17,000 kilometres from the epicentre -- were bigger than those in the Cocos Islands, about 1,600 km south.

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